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The evacuation behavior observed in Kesennuma City, Tohoku, Japan during the Great East Japan Earthquake and Tsunami and a corresponding evacuation simulation are presented. We first organized the damage and evacuation behaviors observed in the target area using the results of previous studies and official surveys. In addition, we compiled all available multimedia sources recording evacuation behavior during the 2011 event to identify the precise temporal and spatial details of the evacuation behavior. Then, a tsunami evacuation simulation was developed based on all compiled evacuation data, considering the tendencies regarding the use of main roads for evacuation, residents' shelter preferences, and pedestrian-car interactions. The developed simulation was validated against the compiled evacuation behaviors by inputting the estimated initial conditions of the 2011 event. The traffic scenarios calculated in the simulation closely reproduced the actual traffic flow as observed from the evacuation data. The evacuee populations at several shelters in the simulation also quantitatively reproduced the trend of the real numbers of evacuees reported by Kesennuma City. The results of the simulation exhibited a better capability to estimate the actual evacuation behavior during the 2011 event than that achieved in previous studies. [ABSTRACT FROM AUTHOR]

Propagation and inundation characteristics of the 2011 Tohoku tsunami on the central Sanriku coast are investigated through field surveys and numerical simulations using offshore wave recordings as incident wave conditions. The numerical model successfully reproduces the extent of flood areas as well as the distribution of tsunami heights along the intricate coastline except for run-up of extreme heights over steep slopes. The survey and computed results suggest significant variations of tsunami heights along the coastline. Their positive dependency on topographic slopes implies that the incoming tsunami propagates in standing wave mode to precipitous sites while in progressive wave mode accompanied by wave breaking over gentle slopes. Temporal-spatial analysis of wave properties in different bays reveals that the inner bay topography provides a clear contrast to inundation characteristics. The impacting waves have extreme heights due to the funnel effect and local wave resonances causing highly transient flooding in narrow V-shaped bays whereas tsunami surges over longer periods across innermost shores of U-shaped bays to produce large horizontal velocities during both run-up and backwash phases. [ABSTRACT FROM AUTHOR]

The field survey results obtained by the team of authors in the north of Miyagi Prefecture between April 1 and 6, 2011 are summarized referring to a part of the survey results by other teams of the 2011 Tohoku Earthquake Tsunami Joint Survey Group. The inundation height above sea level was measured using a laser range finder with a reflection prism. The inundation height was generally larger at bay heads, as well as promontory tips, except several points, which were sheltered by a peninsula or had a tapering area. The tsunamis reached inland far away from the sea along valleys and rivers. Not only steel frame buildings but also many reinforced concrete buildings were collapsed in Onagawa Town. According to the numerical results, the first of tsunamis from the west coast and the second of tsunamis from the east coast should come together in Utatsusaki Peninsula, which is consistent with the interviews to survivors. [ABSTRACT FROM AUTHOR]